With reference to FIG. 1, a conventional heavy duty stationary bicycle 100 comprises usually an H-shaped frame 101, comprising bars 101A, 101B and 101C, with a saddle 102 at its top back corner, a pair of handlebars 103 placed at the top front corner and the two pedals crank mechanism 104 placed at the middle height of the frame under the feet of the rider. The pedal crank mechanism usually drives an inertial wheel 105 (also called flywheel) through a transmission belt or chain 106. The inertial wheel reduces the pedaling speed fluctuations and also through the transmission chain presents the rider with the controllable movement resistance provided by the braking system 107 attached to the wheel. The braking system can be of frictional nature or electromagnetic nature or both. The frame 101 is mounted on a supporting base 108 (made of horizontal bars and/or planks) of a large enough rectangle footprint to make the entire equipment unconditionally (i.e. absolutely) fixed in all three planes of motion. This totally fixed nature of the state-of-the-art stationary cycling equipment reduces to zero all the real balance challenges any rider encounters on a real bicycle which moves in all three planes of motion.
With reference to FIG. 2, another state-of-the-art way of implementing a stationary bicycle is to mount a real (road or mountain) bicycle 200 on a trainer 201. The trainer comprises a support 202, an electromagnetic or friction braking roller 203 upon which the rear wheel of the bicycle 200 rests with strong friction and a fork 204, which holds the rear axle of the bicycle 200 in a fixed position but still allowing it to freely turn. The wheel groove support 205 for the front wheel of the bicycle 200 keeps the horizontal alignment. The rider exerts the effort to work against the braking action of the roller 203. The end result is the same as in the case of the stationary bicycle depicted in FIG. 1 because the road bicycle 200 becomes absolutely fixed in all three planes of motion. The trainer 201 provides absolute support in all planes of motion similar to the support base 108 and acts as the variable braking system similar to the braking system 107 from FIG. 1.
On a real bicycle, although being the smallest movement among the three planes of movement, the most difficult to control movement happens in the frontal plane of the rider (vertical side to side sway movement). This lateral movement or sway of the rider plus bicycle system is the movement which the rider has to learn to control and minimize at all times to avoid crashing to the ground.
Because the goal is to minimize the lateral sway, this movement in the frontal plane of the rider is better described as the main balance challenge for the bicycle rider. Yet, the state-of-the-art stationary bicycle does not exhibit this challenge at all, so it does not constitute a step in any continuous progression aimed at preparing and improving the real bicycle riding skills. It is only a means to train the cardiovascular system and the endurance of the rider by the means of the braking resistance applied to the inertial wheel which the rider has to overcome with the increased legs effort needed to keep the pedals moving. The upper body can be totally relaxed, which is not the case in real riding, where the upper body movement is an essential part in providing the balance of the rider and the bicycle.